High flow liquid filtration device including a porous polyparaxylylene membrane or a porous polyparaxylylene/polytetrafluoroethylene composite membrane

Abstract

A filtration device containing a porous polyparaxylylene (PPX) filtration article is provided. The PPX filtration article includes at least one PPX polymer membrane layer and one or more substrate. Optionally, the PPX filtration article may include one or more support layer(s). The PPX polymer membrane has a pore size from about 1 nm to about 100 nm. The filtration article has a PVA_20 less than about 0.6 cm 3 /m 2 and/or a mass/area (MPA) less than about 30 g/m 2 . The PPX filtration article separates and retains nanoparticles from a feed fluid with high permeability. In use, the PPX filtration article filters nanoparticles from a feed flow by passing the feed fluid through at least one PPX polymer membrane within the filtration article where the nanoparticles are separated and removed from the feed fluid. The PPX polymer membranes may be resistant to chemical attack, gamma radiation, and are thermally stable, biocompatible, and strong.

What is claimed is: 
     
       1. A filtration device comprising:
 at least one polyparaxylylene filtration article including:
 a porous substrate; and 
 at least one polyparaxylylene polymer membrane coupled to at least one side of the porous substrate, 
 
 wherein the at least one polyparaxylylene polymer membrane has a pore size from about 1 nm to about 100 nm, and 
 wherein the filtration article has a volume of pores less than 20 nm per unit membrane area (“PVA 20”) less than about 0.6 cm 3 /m 2  and a mass/area (MPA) less than about 30 g/m 2 , wherein the polyparaxylylene polymer membrane comprises a polyparaxylylene polymer film that has been expanded in one or more directions, and wherein the polyparaxylylene polymer film is an unexpanded polyparaxylylene polymer, and wherein the polyparaxylylene polymer comprises 
 
       
         
           
           
               
               
           
         
          or a combination thereof. 
       
     
     
       2. The filtration device of  claim 1 , wherein the at least one polyparaxylylene polymer membrane has a thickness from about 0.05 microns to about 3 microns. 
     
     
       3. The filtration device of  claim 1 , wherein the at least one polyparaxylylene polymer membrane has a permeability of at least about 0.003 g/cm 2 /min/psi. 
     
     
       4. The filtration device of  claim 1 , wherein the at least one polyparaxylylene polymer membrane has a pore size from about 5 nm to about 50 nm. 
     
     
       5. The filtration device of  claim 1 , wherein the polyparaxylylene filtration article has a PVA 20 from about 0.1 cm 3 /m 2  to about 2.0 cm 3 /m 2 . 
     
     
       6. The filtration device of  claim 1 , wherein the polyparaxylylene filtration article has a mass/area from about 5 g/m 2  to about 30 g/m 2 . 
     
     
       7. The filtration device of  claim 1 , wherein the polyparaxylylene filtration article has a PVA 20 from about 0.1 cm 3 /m 2  to about 2.0 cm 3 /m 2  and a mass/area from about 5 g/m 2  to about 30 g/m 2 . 
     
     
       8. The filtration device of  claim 1 , wherein the polyparaxylylene polymer membrane is a PPX-AF4 membrane. 
     
     
       9. The filtration device of  claim 1 , further comprising a second polyparaxylylene polymer membrane coupled to an opposing side of the porous substrate. 
     
     
       10. The filtration device of  claim 1 , wherein the at least one polyparaxylylene filtration article is positioned within a filtration housing comprising: a fluid inlet configured to direct a feed fluid containing a population of particles into the filtration housing; and
 a fluid outlet configured to direct a filtrate from the filtration housing, 
 wherein the at least one polyparaxylylene polymer membrane is disposed within the filtration housing between the fluid inlet and the fluid outlet and is configured to separate at least a portion of the population of particles from the feed fluid. 
 
     
     
       11. The filtration device of  claim 10 , wherein the at least one polyparaxylylene polymer membrane comprises:
 a first polyparaxylylene polymer membrane coupled to a first side of the porous substrate, wherein the first polyparaxylylene polymer membrane is in fluid communication with the fluid inlet; and 
 a second polyparaxylylene polymer membrane coupled to a second side of the porous substrate, wherein the second polyparaxylylene polymer membrane is in fluid communication with the fluid outlet.